This invention relates to a suspension system of a motor vehicle and more particularly to a suspension system provided with improved two transverse rocker arms.
In the background art of this technical field there is known a wishbone type suspension system used as a front suspension for a motor vehicle such as that disclosed in Japanese Utility Model Laid-open Publication No. 26020/1978. In a wishbone type suspension system, as shown in FIG. 4, two rocker arms constituting an upper suspension arm 1 and a lower suspension arm 2 are swingably mounted to a member of the body of a motor vehicle at the inner ends thereof, i.e. lefthand ends as viewed in FIG. 4. The outer ends of the upper and lower suspension arms 1 and 2 are pin connected to the upper and lower ends of a knuckle member 3, respectively, thus constituting a trapezoidal four-bar linkage mechanism for supporting a wheel of the motor vehicle.
With the wishbone type suspension system of the character described above, the camber variation characteristics in the case of vertical swinging displacement of the suspension system can be changed by changing the lengths of the upper and lower suspension arms 1 and 2 or by changing the vertically pivoting positions of the suspension arms 1 and 2 to the body member of the motor vehicle, the positions being called "inner pivots" hereinafter. However, in actual design, there may arise a case wherein the lengths of the upper and lower suspension arms 1 and 2 are not desirably designed or the vertical positions of the inner pivots cannot be desirably changed because of the limited assembling space in the motor vehicle. For example, when the lengths of the upper and lower suspension arms 1 and 2 are made short, the camber variation becomes large, which creates problems such as excessive wear of whole tires, steering in stability and vibration transmission to the steering wheel of the motor vehicle.